A RELATION OF THE COUPLING COEFFICIENT TO THE EIGENVALUE SEPARATION IN THE COUPLED REACTORS THEORY

A relation of the coupling coefficient with eigenvalues for coupled re actors is given by making use of the rigorous expression for the coupl ing coefficient derived by using the region-wise importance function t o produce fission neutrons. From this relation, an approximate relatio n of the coupling coefficient to the eigenvalue separation of the fund amental and first higher mode is obtained, in which the coupling coeff icient is expressed simply in terms of the difference of the two eigen values. It is shown numerically for simple coupled reactors of one dim ensional slab geometry by comparing with exact values that the accurac y of this relation becomes better as the strength of the coupling betw een cores becomes weaker. (C) 1998 Elsevier Science Ltd.